Removed BBAI function CvTeam::getCurrentMasterPower. Tidied some code.

CvTeam::getCurrentMasterPower was typcially used like this:
    int iPower = isAVassal() ? getCurrentMasterPower() : getPower();
This is cumbersome, and ineffecient because it has to do a vassal check
on all teams for isAVassal, and for getCurrentMasterPower.

The following code gives the same result:
    int iPower = GET_TEAM(getMasterTeam()).getPower();

Also, there could be some confusion between 'getCurrentMasterPower'
and 'getMasterPower', which are completely different functions with
completely different purposes.

So I've deleted CvTeam::getCurrentMasterPower.
CvCityAI::AI_assignWorkingPlots no longer removes all specialists.

Previously, AI_assignWorkingPlots would remove all specialists, and then
reassign the citizens using "addBestCitizen" (perhaps giving them back
the same job anyway). This no longer happens.
Tidied some code and comments. (No functionality changes.)

Tightened the asserts in CvTeam::doesImprovementConnectBonus.
Removed some BBAI comment blocks which surrounded unchanged code.
Made a couple of style adjustments.
Added an avenue for the AI to use to free itself as a vassal.

CvPlayerAI::AI_considerOffer now checks the for denial of existing
vassal deals and returns 'false' if the deal would be denied.

Before this change, AI vassals would never free themselves!

(Note: on closer examination, in the original BtS code, vassals could
free themselves from AI masters but not from human masters, because of
an inconsistence in the way existing deals were being checked. So when I
changed the code to be consistent, I had unintentially taken away the
AI's avenue for canceling vassal deals with anyone at all. Now it is
fixed and better than ever.)

Also, when considering capitualion, the AI will no longer be quite so
afraid of the new master's other enemies. (ie. if the would-be master is
much stronger than the other teams they are at war with, then the
would-be vassal will not use 'we're afraid of your enemies' as an excuse
to refuse capituation.)
CvTeam::getWarWeariness can now include the effect of enemy WW modifiers

Added a new parameter to getWarWeariness: bool bUseEnemyModifer = false.
If bUseEnemyModifer is set true, then the getEnemyWarWearinessModifier
will be used to multiply the return value.
War weariness fix in AI_getWarCommitmentCost. AI_warDiplomacyCost tweak.

The war weariness calculation in AI_getWarCommitmentCost was missing some modifiers.
AI_warDiplomacyCost now adds a negative value if the team has friends already at war with the target.
Tidied some code. No functionality changes.
Made lots of small changes to CvTeamAI::AI_acceptSurrender.

In general, the AI will be a bit less likely to accept a vassal.
Made some further adjustments to CvTeamAI::AI_surrenderTrade.

Adjusted the way 'iAveragePower' and 'iAttitudeModifier' are calculated.
In general, teams will be less likely to offer themselves as vassals.

Made a few minor efficiency / readability changes.
AI_guardCoast now excludes lake plots.

In CvUnitAI::AI_guardCoast, water areas which are too small to be
counted as ocean are no longer counted as plots to be guarded.
This is version 1.35.

Updated the changelog.
Updated the readme.
Fixed the domain type in CvTeam::getTypicalUnitValue.

CvTeam::getTypicalUnitValue wasn't passing eDomain to CvPlayer.
This means the domain type was basically being ignored.
Made some change to how city names are choosen.

When a new city is created, and a name is being chosen from the
civilization's city name list, the search will now skip a name of names
corresponding to the number of cities the player has already founded.
This means that if a player renames a city that they have founded, the
game won't immediately suggest the same previous name for the next city.

Note 1: this only applies to names taken from the civilization city names
list. It does not apply to names on the player-specific city list which
may be used by some mods.
Note 2: previously used names will again
be suggested if the civ's city name list is otherwise exhausted.

Also, if the civilization's list of city names is exhausted, then the
game will suggest a _random_ name from a random civ; rather than the
first available city name from a random civ.
Made some adjustments to the AI's decision making for chopping forests.

The yield produced from chopping is no longer counted in the evaluation
of improvements. This allows us to decide whether or not the new
improvement would be better regardless of potential immediate benefits.

The bChop checks will now be bypassed if the city is building a process.

The value of chopping is now scaled up a bit if the player hasn't yet
reached the target number of cities for the map size.
Made some AI changes in CvCityAI::AI_updateSpecialYieldMultiplier.

The adjustments associated with workboats, workers, and settlers are now
all the same. The effect of building a workboat is now less significant.

GetBetterUnit and EconomyFocus now result in a boost to commerce value.
The 'production' strategy now boosts production and lowers commerce.

Reduced the magnitude of the commerce value reduction when at war; and
made it more conditional. Also, increased the productivity value boost
for war when using dagger or crush.
Short-circuited some unneccessary calls to CvCitAI::AI_commerceWeight.

Added conditions to bypass some calls to AI_commerceWeight when it would
only have been used to multiply zero.

Also, fixed an original BtS bug in CvPlayerAI::AI_techValue which caused
all new processes to be identified as being "good".
CvPlot::getYieldWithBuild now counts 'extra yield'. (eg. from financial)

It still does not count the bonus yield from golden-ages.
Fixed a misuse of getGoldPerTurn in CvPlayerAI::AI_commerceWeight.

CvPlayer::getGoldPerTurn refers only to gold from trade deals. The value
that AI_commerceWeight really wanted was calculateGoldRate.
(Unfortunately, the corrected version is slightly slower. - But at least
it makes sense!)
Added function AI_getAvailableIncome. Replaced old code for consistency.

AI_updateAvailableIncome calculates and caches an estimate of the total
gold-per-turn revenue the player could achieve if they used 100% gold on
the commerce slider. This function is called once per turn, and the
result is accessed with AI_getAvailableIncome.

AI_getAvailableIncome is now used to replace some previous income
estimates which typically worked by simply adding
getCommerceRate(COMMERCE_SCIENCE) + getCommerceRate(COMMERCE_GOLD) + std::max(0, goldPerTurn())
The old calculation was flawed in that it failed to correctly handle
espionage or culture on the commerce slider.
Corrected the position of the new era screen.

Apparently 'centerX' only works if the screen is size 1024; and so my
previous attempt to center the new era screen was actually putting it
left of center.